Friday, December 02, 2011

Study Reveals Graphene’s Novel Reaction to Light

MIT researchers have revealed that graphene can generate electric current in uncommon ways when sparked by the energy of light. The finding paves way to a novel method for electricity production from sunlight and enhances night-vision systems and photodetectors.

Pablo Jarillo-Herrero, one of the MIT researchers, stated that scientists had already found the current-producing effect of graphene but they believed that it was caused by a photovoltaic effect. However, the MIT scientists observed that illuminating light on a graphene sheet makes it to have two regions with dissimilar electrical characteristics, which in turn generates differences in temperature and eventually produces an electrical current.

According to the finding, graphene can also be used to detect biologically significant molecules, including food contaminants, disease vectors and toxins, most of them produce infrared light during illumination. Graphene can be comparatively inexpensive to other detector materials such as semiconductors. As it responds to an extensive range of wavelengths, graphene can effectively collect solar energy, said Jarillo-Herrero. However, further research will be required, as it is still not clear that the material can efficiently produce energy, he added. The factors that can enable graphene photodetectors faster or better will now be the focus of further research, he added. The Air Force Office of Scientific Research backed the research work, which also received funds from the Packard Foundation and the National Science Foundation.